We have numbers 8950 and 7640. Let's start adding them together.

Step 1: We'll start by adding the digits 0 & 0 in column 1 and get 0.

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 9.

Step 3: We'll start by adding the digits 9 & 6 in column 3 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 7 in column 4 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

So, 8950 + 7640 = 16590.

